The invention relates generally to electric motors and, more particularly, to alignment of a motor and rotating shaft of a driven device through an intermediate material.
Alignment of a motor and its rotating shaft so that they share an axis of rotation is important for safe, efficient operation of a motor. The purpose of alignment is to ensure that the centerline of the motor coincides exactly with the centerline of the driven rotor shaft. Alignment is essential to ensure that a machine runs smoothly with minimum vibration, as misalignment of the motor and rotor shaft can produce excessive vibration and high temperature, which can lead to premature failure of bearings, couplings, or the shaft. Alignment has to be done whenever the motor or driven machinery is dismantled or even when the machines are not running smoothly.
Proper alignment of a motor and its rotating shaft can be made more difficult when an intermediate material is included/positioned between the motor and shaft. A common example of such an arrangement is where a motor is positioned on the outside of a volume and a rotating shaft is positioned on the inside of a volume, with a housing therebetween. While most motors have a shoulder or hub thereon for aligning them with the shaft, often times this hub is not deep enough to function with the presence of an intermediate material between the motor and shaft.
A specific example of where an intermediate material is included/positioned between a motor and shaft can be found in a computed tomography (CT) imaging environment. More specifically, in many CT imaging systems a pre-patient collimator is used for shaping the x-ray beam from an x-ray source is employed. The pre-patient collimator includes a pair of blades positioned within a housing and that are adjustable relative to one another so as to vary the size of an aperture formed therebetween for allowing the x-ray beam to pass therethrough. An electric motor positioned outside the housing is provided for adjusting the blades, with the electric motor mating with a shaft positioned within the housing and connected to the blades in order to rotate the shaft and adjust the blades in response to that rotation. In the pre-patient collimator, a layer of radiation blocking material is positioned as an intermediate material between the housing and the motor to prevent excess radiation from escaping the housing into the motor or elsewhere. Thus, in many instances, it can be difficult to properly and efficiently align the motor and collimator blade shaft in a pre-patient collimator.
Therefore, it would be desirable to provide a component that enables alignment between a motor and a separate rotating shaft through one or more intermediate layers. It would also be desirable for such a component to protect the rotating shaft, provide a hard stop for moving components, and provide an easy means for disassembling the component from the motor and/or rotating shaft without the use of unique tools.